Although hard disk drives are widely used in current computer system, there are still a variety of deficiencies for the rotating-type magnetic mass storage devices, such as deficiencies of an inherent latency during accessing the hard disk drives, high power consumption, being unable to withstand the physical shock, and having a large weight for portable computer devices.
A non-volatile memory mass storage device, like a flash memory disk drive, is a nice choice for replacing a hard disk. Each memory mass storage device always comprises two portions; one is a controller part, and the other is a memory module. The semiconductor technology allows such a memory storage device to withstand many of the kinds of physical shock and reduce power consumption or weight. These flash memory storage devices are also widely used and accepted for all the current computer devices, like desktop personal computer (PC), laptop, personal digital assistant (PDA), digital camera, and soon.
Each of current mass storage devices, no matter hard disk drives or memory storage devices, is always configured as a mass storage drive by the host. This drive could be partitioned into a plurality of “logical” drives by the host. For example, the host just executes a “partition program” and then the partition information is written into the drive. When next time power-on, such a drive partitioned by the host will be recognized as multiple “logical” drives.
From the host point of view, a drive is composed of a plurality of logical blocks, and the partition information is generally located on the first block, logical block address 0(LBA 0). If the first block is defective or infected by the computer virus, all of the logical drives indicated by the partition information may not be detected by the host. It is a risk for a drive partitioned into multiple logical drives by the host.
Furthermore, because the host can freely access all the data, some important files, like system files, may be deleted by careless end users. For another aspect of this case, the right of data access is too open to meet the private or security requirements. It is another risk or inconvenience.